DNR retiring Wild Rose trout, adopting new strain

So goes the rumor that trout in the Sturgeon River, whose headwaters begin in Otsego County and dumps into Burt Lake at Indian River, can be a little coy.

That can be frustrating for anglers, but an attractive quality in a fish for the Department of Natural Resources (DNR), which is eyeing the shy salmonid as a parent class for its future generations of stocked fish.

“They’re a Michigan strain of trout, well adapted, and hopefully, they’ll do better, grow better, survive better and provide a better return for anglers,” said study leader Todd Wills, fisheries research biologist for the Lake St. Clair Fisheries Research Station in Harrison Township.

Currently, the DNR stocks a strain of brown trout called “Wild Rose” after the hatchery in Wisconsin where they were originally bred. Over the past 50 years, the trout have become inbred, relatively docile and susceptible to disease.

“They’re a hodgepodge of a bunch of different strains,” said Dan Sampson, hatchery biologist with the Oden State Fish Hatchery in Oden. “The broodstock we have have never been wild in Michigan.”

The DNR first stocked two rivers with this new, wild strain — the AuSable River below the dam at Mio and the Manistee River below Hodenpyl Dam near Mesick — in the spring of 2010.

When biologists returned in the fall of 2010 and fall of 2011 to shock the rivers, they found a hopeful result. This fall’s first sweep of the AuSable below Mio — known as the trophy waters among anglers — returned 800 total fish, 300 of which were the Sturgeon River strain, 400 of which were wild, and less than 100 were the Wild Rose strain.

The Manistee shocking sweeps returned fewer fish, but, in addition to a “handful of wild fish, we only saw the Sturgeon River strain,” Wills said.

“Shocking” refers to the process of electrofishing, where Fisheries staff wade the river and use electrically-charged wands to send electricity through the water, stunning fish long enough to be captured. Once measurements are taken and fish are marked with a fin clip they’re set free healthy and unharmed.

Wills’ study began in 2006 with teams shocking the Sturgeon River below Wolverine to find a fish that might be used to produce a new hatchery strain. Previously, fisheries managers weren’t happy with the returns of Wild Rose brown trout anglers were seeing on lakes and rivers.

It also comes to genetics. Because the DNR knows exactly where the parent class of the Sturgeon River strain came from, biologists can go back into the Sturgeon River and get new genetic material.

“Now we’ve learned that if you continue to inbreed these fish generations after generations, negative traits pop up. They don’t perform well in the hatchery,” said Mark Tonello, research biologist out of the DNR’s Cadillac Operations Service Center, which oversees the Manistee River.

The fish also seem to get used to hatchery life, where caretakers fling fistfuls of food at them.

“The Wild Rose fish are your prototypical dumb hatchery fish,” said Tonello. “When you throw food at the Wild Rose, they come running. The Sturgeon River’s are completely different. They are very shy and very flighty when you throw food at them.”

If the Sturgeon River’s become adjusted to hatchery life, biologists can inject new, wild genetic material into subsequent generations.

Though the new fish could spell trouble for anglers — Sampson said the DNR’s shocking for the parent broodstock back in 2006 found four or five brown trout per hole on the Sturgeon where before some anglers would swear there were none — the wilier fish could naturally reproduce in more rivers, helping the DNR to cut down on stocking fish.

“The Wild Rose grow really well and are caught pretty easily. The Sturgeon River’s are not that way. They’re a very skittish fish, very afraid and very alert,” said Sampson. “Because of that, they may do much better once we stock them, but may not be caught as well, either.”

— Morgan Sherburne is an avid outdoorswoman and features and sports writer for the Petoskey News-Review. She can be reached at 231-439-9394 or msherburne@petoskeynews.com. Her column appears every other Saturday in the Herald Times.